Existing industrial products, such as wires, cable, tubes, ropes and similarly elongated products which are manufactured in continuous linear processes, are preferred to be measured by non-contact methods, to determine the overall size as well as the surface integrity of the profile of the product.
These measurements usually take place while the products are being manufactured, such as during extrusion, in the case of plastic cables, tubes etc., or drawing, in the case of wires, metallic tubes and the like. Measurements at the point of manufacture are necessary, firstly to ensure compliance to specification requirements, and secondly to check on the surface integrity of the finished product.
The primary measurement applied to linearly manufactured elongated products is the diameter or size of the product, and this is done preferably by optical non-contact devices. Quality control, or surface integrity of the product, is performed in a similar manner by an optical device, whereby the profile of the product is examined to ensure that there are no faults or damage, such as ridges, valleys and the like, in the surface of the product.
In the prior art in existence at the time when the present invention was envisioned, two alternative optical systems existed, one for dimensional measurements of the product and an alternative system for checking the surface integrity of the product. These prior art systems will be explained later in this text. Both types of prior art systems, however, suffered from low maximum scanning frequencies that hinder the ultimate resolution with which they are able to detect defects and provide measurements due to the nature of their design. This has become especially troublesome in modern manufacturing lines which run at very high speeds, with such speeds only increasing each year.
What is needed, therefore, are techniques to increase the scanning frequency of optical dimensional measuring devices suitable for measuring the diameter or size of a moving product while simultaneously verifying the surface integrity of the product, during the manufacturing process of the product which can provide adequate resolution on modern, high-speed, production lines.